Physical and chemical monitoring of the waters pollution of the sub basin of the lower Sebou, Gharb, Morocco



In Morocco, hydraulic and hydrological studies of rivers are rare. In the present study, it is proposed to characterize the physic and chemical surface water of the sub basin of the lower Sebou. The study of the raw waters of the Sebou revealed that this Oued is very loaded with mineral matter. For the electrical conductivity (EC), a wide variation in the chemical composition of the water varies between a minimum of 629 μS/cm and a maximum of 2370 μS/cm. The average pH is between 8 and 8.77. The pH is slightly basic but remains acceptable according to Moroccan irrigation standards. The ammonium concentration varies between 0.04 and 2.66 mg/L, for surface water quality 65% of the water is of medium quality and 35% of poor quality. Concentrations of NO3- nitrates have a maximum value of 196.9 mg/L and a minimum value of 0.24 mg/L. It has also been found that the concentration of Cl- ion has a maximum value of 385.53 mg/L and a minimum value of 145.55 mg/L. For SO4-- sulfate ion concentrations, the maximum value is 359.29 mg/L and the minimum value is 37.62 mg/L. The maximum and minimum bicarbonate ion concentrations are 362.34 mg/L and 75.64 mg/L and are consistent with the irrigation standard. Calcium Ca2+ ion contents range from 220.4 to 97.6 mg/L. For magnesium ion concentrations Mg2+ the maximum value is 124.08 mg/L and the minimum value is 17.28 mg/L and these values are in line with the irrigation standard. Na+ ion concentrations in water range from 51 mg/L to 2530 mg/L. K+ ion concentrations in surface waters range from 17.55 mg/L to 2.54 mg/L. In conclusion, this study shows that the waters of the lower Sebou have a high mineral load but remain within the limits of the Moroccan irrigation standard. The waters of the Sebou are too polluted and we recommend that all domestic and industrial wastewaters be treated appropriately to reduce the nuisance to the receiving environment and to compensate for the loss of this coveted and prized.


Surface Waters Physicochemicals, Sebou river, Quality, Gharb, Morocco

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